Zed has plenty of options. He's not being forced out of the game. He's doing fine. He has the potential to instantly delete anyone who doesn't itemize against him (and still severely threaten anyone who does) and then escape back to total safety. There aren't any AD carries who can do that. They get other options.
Zhonya's is one of the strongest items in the game. Big deal. It's not making any one class dominant over another, and it fills a defensive option for a class that is very often limited on mobility. This is comparable to ghostblade and bork giving great chasing and dueling potential to AD assassins.
Zed is more than capable of having the entire game "tremble at his feet depending on him for the win". He can completely take over games. Do not try to tell me he's lacking right now. That holds no water with me.